Apache Kafka Experts in Germany

• Proactive support of management in business field development & innovation management

• New development of a suite of business applications for analyzing valuation, P&L, and market price risk data

• Automation of all internal and external business and work processes

• Development of AI-based and AI-supported ETL processes as well as data analysis

• Business use-case development

• Business and work process optimization

• Enterprise architecture management

• Sales data analysis and forecasting as well as capture

• Inventory management & reordering

• Supplier management and communication

• Customs processing & clearance

• Shipping handling & warehouse coordination

• Interface management

• Technologies used: Microsoft Office 365, Microsoft Teams, JTL-Wawi, JTL-WMS, OTTO Partner Connect (OPC), Amazon Seller Central, DHL Global Forwarding, Jira, Draw.IO, Java (8,17,21,25), Jenkins, SonarQube, Git, Gitea, Spring Boot, Spring Batch, Vaadin, H2, PostgreSQL, Docker, Local LLMs, Postman, JasperSoft Studio, JasperReports

• Development of cloud native applications to provide a multi-vendor marketplace for different digital assets (e.g. NFTs)
• Design and operation of a microservice architecture using Nest.js, MySQL, Redis, Hasura, Algolia, Docker and Serverless
• Design and operation of a streaming data architecture using Kafka (with JSON Schemas)
• Creation of CI/CD pipelines with GitHub Actions for automated deployment of applications
• Testing and evaluating new technologies for more stable, faster, safer and more sustainable application development
• Building the full infrastructure with Terraform in AWS
• Integration of Stripe to handle international payments
• Use of Algolia for real-time search of digital assets on the platform
• Presenting results to stakeholders and running internal meetups
• Federation of services with GraphQL and Hasura
• Discussions about architecture decisions in the IT landscape and their impact
• Use of message queues for app-internal communication and component encapsulation
• Advising internal staff on the implementation of business and technical requirements
• Test Driven Development: unit, integration and E2E testing using JUnit
• Use of Next.js/React with SASS/SCSS for frontend applications
• Use of Vue.js with SASS/SCSS for frontend applications
• Integration of security-related mechanisms (JWT tokens with Auth0, OAuth, OIDC, IP guards, BOLA, secret vaults)
• Creation of microfrontends using Retool for fast prototyping and testing of functionality
• Use of nx monorepo with nrwl

• IT systems: Azure DevOps, SharePoint, Opal/Repost, JustinMind, Monday, SAP

• Analysis of requirements for branch software

• Coordination of intercultural teams

• Partly agile project organization

• Master data management / DMS

• UI/UX design and mockup creation

• Requirements documentation

• Digitalization of signatures

• Stakeholder management and workshop facilitation

• Billing/bank transfer

• Business analysis / requirements engineering

• Further development of the existing e-commerce platform based on SAP Commerce (Hybris) to meet the growing demands of digital commerce.
• Ensuring the scalability and performance of the backend, so the platform remained stable and efficient even under heavy user load.
• Development and integration of new OCC REST APIs and services for modular extensions and flexible adjustments, to implement new features quickly.
• Optimization of data flows and interfaces, which significantly improved platform efficiency and system performance.
• Ensuring a maintainable and scalable code base by using Clean Code principles, proven design patterns, and a future-proof architecture.
• Reduction of errors through extensive testing with JUnit, Mockito, and load tests with Gatling, supported by the introduction of automated test processes.
• Improved system performance through targeted refactoring measures and efficient database queries, especially to handle peak loads.
• Use of modern cloud and monitoring tools such as Kubernetes, Google Cloud Platform (GCP), and Grafana to ensure a stable and monitored infrastructure.
• Clear improvement in efficiency, scalability, and reliability of the platform, which now meets the demands of a dynamic and growing e-commerce market.

With project PRIZMA, DB will modernize its infrastructure on the one hand, and develop a fail-safe IT landscape on the other hand, which can be restored quickly and securely in case of a disaster.

• Capture current architectures of existing systems as well as methodical consulting and development of target architectures
• Deepen and maintain the building plan / target IT landscape
• Implement technical architecture concepts & architecture descriptions
• Implement migration concepts for updating and further developing the platform and information systems
• Assess submitted improvement suggestions as part of the project
• Capability management: identify capability gaps, develop target visions, and support transformation planning within the enterprise architecture.
• Create a compatibility matrix of the components in use and compare dependencies of specific versions
• Create an IT concept for extending the platform with the following topics: hardware and software requirements, security, licensing, high availability, load balancing, backup & recovery, update strategy, monitoring integration, etc.
• Coordinate with business architects as well as technical architects from the cross-functional architecture area of the PRISMA program for the topics (backup, Active Directory, monitoring, Citrix, and business applications ...)
• Status meetings and alignment of project planning with the Release Train Engineer / Project Manager
• Advise the Release Train Engineer / Project Manager in identifying project risks
• Advise the System Architect Engineers in steering the implementation of the concept
• Implement the IT concept
• Document the infrastructure

Label: MS Project, LINUX, Windows, ORACLE, Java, REST, SharePoint, Microsoft Exchange, UML, Enterprise Architect, BPMN, AZURE, AWS, V-MODEL, Micro Service, VisualStudio, SAP S/4HANA, SCRUM(SAFE), ESB (TIBCO), Python, Innovator, LeanIX (TOGAF), Ansible, Ansible Tower, Ansible Automation, ROBOT, SpringBoot

• Analysis of affected business processes taking numerous stakeholders into account
• Interface analysis, architecture and system design
• Communicating and coordinating various subprojects and interface partners
• Creating epics and user stories, maintaining the backlog, workshops and review presentations
• Support during implementation between business departments and development
• Test management including strategy and approach definition
• Test case definition, execution and approval
• Cross-team organization of integration and acceptance tests
• Support of test environments
• Technologies and tools: Java, Angular, Kubectl, REST, AWS SNS/SQS, Kafka, S4/HANA, Bruno

• Building a data integration platform for high, medium, and low voltage assets for contextual analysis of time series with master data from the SCADA control system (IEC 60870 104), INIS, and SAP.
• Responsibility for the architecture and implementation of the solution, as well as sparring partner for the Product Owner.
• Use of Kotlin, Spring Boot, Maven, TimescaleDB, PostgreSQL, liquibase, Elements IoT, Docker, Kubernetes, Grafana, Python, jupyter, and various API gateways.

• Development of a browser-based platform for no-code deployment and cluster management in Kubernetes
• Implementation of a CLI tool in TypeScript to provision resources directly from the browser interface into the cluster
• Development of a expression parser in Go and delivery as a microservice to extract Helm expressions from values files
• Use of LLMs to turn user intent into Kubernetes diagrams
• Technology stack: Java, Go, OpenAI API, React, Azure, Next.js, Strapi, Stripe Connect

• Team leadership: Prioritization and coordination of four cross-functional teams.
• Platform strategy: Development and implementation of strategies to optimize existing IT platforms.
• Stakeholder management: Active management of expectations and communication with internal and external stakeholders.
• Program and innovation management: Prioritization and coordination of cross-department projects as well as innovation initiatives.
• Product Owner consulting: Advising Product Owners with a focus on product development and continuous product improvement.
• Organizational development: Improving communication and decision-making structures across all organizational levels.
• Change management: Implementing best-practice change management methods to ensure continuous optimization and innovation.
• Quality assurance: Ensuring high quality standards in processes, services, and deliverables.

I am an experienced data engineer specializing in end‑to‑end data integration, cloud DWH architectures, and high‑quality, governed data products.

I delivered following projects and engagements as a freelancer.

• Data Migration of CRM System for AL-FA Objekt Service Gmbh
• Microsoft Software Resales Partnership

I am looking for freelance roles like: Freelance Data Engineer Cloud Data Warehouse Architect Data Modeling & Architecture Consultant MDM & Data Governance Specialist BI & Analytics Developer

Technical Focus Areas

• Data Engineering & Integration: SQL Server/SSIS, Informatica PowerCenter/IDQ, Talend, Kafka, Azure Data Factory – Delta/CDC/ELT patterns, robust pipelines, monitoring/recovery, data lineage & impact analysis, medallion architecture Bronze/Silver/Gold layers
• DWH & Cloud: Azure SQL / Data Lake / Synapse, AWS Redshift/S3, on‑prem SQL/Oracle – scalable data marts with a strong cost/benefit focus.
• Data Modeling: Atomic (Inmon) and Dimensional (Kimball), Data Vault (Linstedt), Domain‑Driven Design, clear lineage & contracts.
• MDM & Governance: Informatica MDM, IBM MDM, stewardship processes, data quality rules, survivorship/XREF, catalog/glossary, SIF/BES/REST publication.
• Analytics/BI: Power BI, SSAS, Cognos – business‑ready, maintainable data products.

• Ride-sharing and bus platform, live and working. Backend Spring Boot 4.1 on Java 21, PostgreSQL with Flyway, Testcontainers integration tests. Running in my own AWS account (ECS Fargate, ALB, ECR, IAM least privilege) with CI/CD via GitHub Actions and OIDC federation without static credentials. Development throughout AI-assisted with Claude Code, including my own skills and project-specific memory. Spring Boot · Java 21 · PostgreSQL · Flyway · Docker · AWS ECS/ALB/ECR · CI/CD · GitHub Actions · Claude Code

• Architected the Yatta Integration Layer – a config-driven integration platform on Java 25, Spring Boot 4 (WebFlux), Temporal, gRPC and Kafka, enabling new third-party integrations (e.g. AVS fulfillment) via declarative JSON configs with zero code changes.
• Designed and implemented Tink integration with 0Auth IBAN verification to enhance fraud prevention and account validation workflows with Adyen payByBank.
• Architected and implemented an OpenFGA-based authorization model for centralized management of users, groups, and fine-grained access control in the vendor portal.
• Architected and led delivery of the Yatta API Gateway platform using GraphQL Federation, providing a unified enterprise API layer across distributed microservices with centralized authentication, authorization and request orchestration.
• Replaced NGINX + NLB with Istio service mesh and AWS ALB; rolled out WAF, OAuth (Cognito), IP whitelisting and RBAC across environments.
• Migrated CDC from Confluent Cloud connectors to a self-hosted Kafka Connect + Debezium stack, reducing operational cost by ~80% across multiple environments.
• Implemented the Transactional Outbox pattern with Debezium for reliable, exactly-once event publishing to Kafka with Avro and Schema Registry.
• Migrated dunning/payment-recovery workflows from Airflow to Temporal, achieving 99.9% reliability for settlement handling.
• Optimised Apache Airflow with deferrable sensors to handle 1000+ concurrent DAG runs without scaling the worker pool.
• Refactored a monolithic Terraform codebase into 3 modular projects, cutting deployment time by ~45%.
• Stood up full observability with OpenTelemetry, Tempo, Prometheus and Loki; automated dev/staging/prod with ArgoCD, Image Updater and Helm.
• Collaborated with product, operations and engineering stakeholders to define scalable platform architecture and integration standards aligned with long-term business and operational goals.

• Training the AI models, evaluating images and texts for UI/UX, turning the provided data into insights via OpenAI Feather as part of the machine learning workflow

Technologies: OpenAI Feather

• Short description: Leading a group-wide project to establish standardized cloud governance for Microsoft Azure, including policies, security and compliance controls, automation, and cost and operations management while preserving the autonomy of decentralized business units within regulatory frameworks.

• Tasks and activities:

• Overall responsibility for designing, building, and implementing a company-wide cloud governance structure (Azure), including target picture, roadmap, and operating model.

• Managing internal and external stakeholders (C-level, IT, Security, Compliance, Cloud Architecture, DevOps), including decision and escalation management.

• Planning and facilitating workshops on cloud strategy, governance principles, and the design of areas such as identity, connectivity, and platform management.

• Defining, implementing, and rolling out cloud policies (Azure Policy / custom policies), security standards, and compliance requirements (including GDPR, ISO 27001, BSI C5).

• Building a cloud governance framework based on the Azure Cloud Adoption Framework (CAF), including landing zone and guardrail concepts.

• Introducing automation solutions for governance, security, and cost control (policy/control automation, IaC, CI/CD-based control mechanisms).

• Implementing cloud security and compliance monitoring mechanisms as well as continuous improvement processes.

• Establishing and operationalizing FinOps in an enterprise environment (central and decentralized FinOps teams), including cost management strategies, reporting, and guardrails.

• Integrating governance policies into DevOps processes (e.g. CI/CD principles for security and compliance checks, GitLab Runner concept in spokes, GitLab CI/CD for CAF landing zones).

• Implementing access concepts including RBAC design and breaking-glass mechanisms (emergency access) as well as certificate automation (ACME / step-ca).

• Achievements:

• Created a unified, auditable governance and control set for Azure (policies, standards, compliance mapping) and thus laid the foundation for scalable cloud use in a regulated environment.

• Established repeatable automation for governance, security, and cost control (IaC + CI/CD), reducing manual effort and implementation risk.

• Improved operational and decision-making capability across central and decentralized units (clearer roles, responsibilities, escalation paths, balance between autonomy and group requirements).

• Significantly increased workload compliance during lift-and-shift migrations.

• Technologies used:

• Microsoft Azure Policy, custom policies.

• Terraform, OpenTofu, Terragrunt.

• step-ca (ACME).

• Entra ID.

• Azure Firewall.

• Azure Networking, hub-and-spoke architecture.

• Azure vWAN (evaluation).

• Azure Front Door, Azure Application Gateway.

• Azure ExpressRoute.

• Azure Key Vault.

• NetBox.

• GitLab (on-premises).

• Infrastructure, concepts used:

• Cloud shared responsibility model.

• Hub-and-spoke connectivity / central shared services (from hub-spoke context).

• Central governance with decentralized delivery (business unit autonomy with guardrails).

• Methods used:

• Scrum.

• Stakeholder management (C-level to engineering).

• Cloud governance, Azure Cloud Adoption Framework (CAF).

• DevOps, CI/CD.

• Cost and FinOps approaches: tagging/chargeback models, budget/alert concepts, reserved instances/savings plans vs. on-demand scenarios, sensitivity analyses.

• RBAC, breaking-glass concepts.

• ACME / certificate automation.

• GitLab Runner concept in spokes, GitLab CI/CD pipelines for CAF landing zones.